refactor(util): fine tune ImeUtils (InputMethodUtils)

app/src/main/java/com/osfans/trime/common/InputMethodUtils.kt

@@ -0,0 +1,47 @@
+package com.osfans.trime.common
+
+import android.content.Context
+import android.content.Intent
+import android.provider.Settings
+import android.view.inputmethod.InputMethodManager
+import timber.log.Timber
+
+object InputMethodUtils {
+    private const val IME_ID: String = "com.osfans.trime/.TrimeImeService"
+
+    fun checkIsTrimeEnabled(context: Context): Boolean {
+        val activeImeIds = Settings.Secure.getString(
+            context.contentResolver,
+            Settings.Secure.ENABLED_INPUT_METHODS
+        ) ?: "(none)"
+        Timber.i("List of active IMEs: $activeImeIds")
+        return activeImeIds.split(":").contains(IME_ID)
+    }
+
+    fun checkisTrimeSelected(context: Context): Boolean {
+        val selectedImeIds = Settings.Secure.getString(
+            context.contentResolver,
+            Settings.Secure.DEFAULT_INPUT_METHOD
+        ) ?: "(none)"
+        Timber.i("Selected IME: $selectedImeIds")
+        return selectedImeIds == IME_ID
+    }
+
+    fun showImeEnablerActivity(context: Context) {
+        val intent = Intent()
+        intent.action = Settings.ACTION_INPUT_METHOD_SETTINGS
+        intent.addCategory(Intent.CATEGORY_DEFAULT)
+        intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
+        context.startActivity(intent)
+    }
+
+    fun showImePicker(context: Context): Boolean {
+        val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager
+        return if (imm != null) {
+            imm.showInputMethodPicker()
+            true
+        } else {
+            false
+        }
+    }
+}

app/src/main/java/com/osfans/trime/settings/PrefMainActivity.kt

@@ -214,26 +214,22 @@ class PrefMainActivity :
     class PrefFragment : PreferenceFragmentCompat() {
         override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
             setPreferencesFromResource(R.xml.prefs, rootKey)
-            if (ImeUtils.checkIfImeIsEnabled(requireContext())) {
+            if (InputMethodUtils.checkIsTrimeEnabled(requireContext())) {
                 findPreference<Preference>("pref_enable")?.isVisible = false
             }
-            if (ImeUtils.checkIfImeIsSelected(requireContext())) {
+            if (InputMethodUtils.checkisTrimeSelected(requireContext())) {
                 findPreference<Preference>("pref_select")?.isVisible = false
             }
         }
 
         override fun onPreferenceTreeClick(preference: Preference?): Boolean {
             return when (preference?.key) {
                 "pref_enable" -> { // 啓用
-                    val intent = Intent()
-                    intent.action = Settings.ACTION_INPUT_METHOD_SETTINGS
-                    intent.addCategory(Intent.CATEGORY_DEFAULT)
-                    startActivity(intent)
+                    InputMethodUtils.showImeEnablerActivity(requireContext())
                     true
                 }
                 "pref_select" -> { // 切換
-                    (activity as PrefMainActivity).imeManager.showInputMethodPicker()
-                    true
+                    InputMethodUtils.showImePicker(requireContext())
                 }
                 "pref_schemas" -> {
                     SchemaPickerDialog(requireContext()).show()
@@ -245,10 +241,10 @@ class PrefMainActivity :
 
         override fun onResume() { // 如果同文已被启用/选用，则隐藏设置项
             super.onResume()
-            if (ImeUtils.checkIfImeIsEnabled(requireContext())) {
+            if (InputMethodUtils.checkIsTrimeEnabled(requireContext())) {
                 findPreference<Preference>("pref_enable")?.isVisible = false
             }
-            if (ImeUtils.checkIfImeIsSelected(requireContext())) {
+            if (InputMethodUtils.checkisTrimeSelected(requireContext())) {
                 findPreference<Preference>("pref_select")?.isVisible = false
             }
         }